Evidence continues to accumulate that dementia – until now untreatable – can be kept at bay by physical activity.
A study from Rutgers University in New Jersey has confirmed the positive effects of exercise on insulin-signalling proteins from the brain.
Specialised cells involved in how the body responds to insulin, are activated in the brain after exercise, suggesting that physical activity therapies targeting this insulin action may be developed to offset or even prevent dementia progression.
The researchers focused on the role of neuronal extracellular vesicles, cells released by the brain that facilitate transport of key molecules such as proteins between cells, in particular one called Akt.
People with pre-diabetes were given a glucose drink before and after a one-hour training session of moderate to vigorous physical activity, and then the vesicles in their blood were isolated and studied.
The blood samples showed that the number of neuronal vesicles carrying proteins involved in insulin sensitivity increased after each training, with Akt being most notable.
“We showed for the first time that exercise impacts insulin signalling from neuronal extracellular vesicles in relation to clinical improvements in blood sugar,” said Steven Malin, an associate professor in the Department of Kinesiology and Health in the Rutgers School of Arts and Sciences and lead author of the study.
Exercise, therefore, is potentially able to improve the brain’s capacity to respond to insulin for neuronal function, he said.
“We believe this work is important because it suggests exercise may work to improve cognition and memory by improving the abilities of insulin to act on the brain,” he said.
"Those with pre-diabetes run the risk of having insufficient levels of insulin in their bodies, particularly the brain, which increases the chances of developing diseases of dementia such as Alzheimer’s, Malin said.
Exercise has long been believed to improve cognition, but the mechanisms involved have been unclear. Past studies have uncovered evidence that high blood sugar contributes to a decrease in the brain’s ability to recall information and learn new information.
Malin said that insulin, which is produced by the pancreas and travels to the brain to perform its functions, plays a central role in promoting brain blood flow and neuronal functioning for cognition.
“Our work suggests that therapies that target brain insulin action may be able to ward off dementia,” Malin said.
Another recent study found people who participate in moderate to vigorous physical activity may be less likely to develop not only dementia, but, stroke, anxiety, depression, and sleep disorders.
From a large United Kingdom database at Biobank, researchers looked at data from 73,411 people with an average age of 56 who wore accelerometer devices continuously for seven days to measure their physical activity, how much energy they used on their activities and how much time they spent sitting each day.
People who had moderate to vigorous physical activity energy expenditure were 14% to 40% less likely to develop these diseases than those who had lower energy expenditure, depending on how active they were.
The people who did not develop any of the diseases had an average daily moderate to vigorous physical activity energy expenditure of 1.22 kilojoules per kilogram, compared to 0.85 for the people who developed dementia, 0.95 for those who developed sleep disorders, 1.02 for stroke, 1.08 for depression and 1.10 for anxiety.
The Rutgers Study, in collaboration with National Institutes of Health’s National Institute on Aging, is published in Aging Cell. https://onlinelibrary.wiley.com/doi/full/10.1111/acel.14369
The Biobank study will be presented at the American Academy of Neurology annual meeting in April. https://aanfiles.blob.core.windows.net/aanfiles/56bf3add-5deb-4b9ead6f3193bdafe3ba/2025%20AAN%20Annual%20Meeting%20Abstract%20%20Physical%20Activity%20and%20Neuropsychiatric%20Diseases
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